JPH05125339A - Automatic falling type masking material - Google Patents

Abstract

PURPOSE:To provide the subject masking material comprising a support layer, a foaming agent-containing pressure-sensitive adhesive layer disposed on one surface of the support layer, and a shrinking substrate layer having heat- conductive holes on its whole surface and disposed on the other, efficiently conducting heat when heated, and accelerating the thermal foaming of a foaming agent. CONSTITUTION:The objective masking material is constituted of a support layer 2, a pressure-sensitive adhesive layer 3 containing a thermally foamable foaming agent (e.g. ammonium carbonate or azobisisobutyronitrile), and a shrinking substrate layer 4 comprising a thermally shrinkable raw material (e.g. polyethylene) and having heat-conductive holes 41 disposed on the whole surface of the layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic captive masking material, and an object thereof is to provide an automatic captive masking material that can be easily and reliably unattended after attachment, and is particularly suitable for automobile protection. The use of this automatic removal type masking material for the undercoat masking work such as the wiring harness wiring hole portion when applying rust paint contributes to the rationalization and systemization of this work.

[0002]

2. Description of the Related Art Conventionally, when coating an automobile anticorrosive paint, the wire harness wiring hole is manually masked with an adhesive tape in order to prevent the paint from flowing out from the wire harness wiring hole. The method of painting was widely used.

However, this manual masking work is a work that requires the attachment of about 100 holes per vehicle in a short time, and is very complicated and requires skill. .. For this reason, automation of this masking work came to be performed, and a method of using a masking material with adhesive processing on Styrofoam was created, but this method also performs the "piercing and peeling" process of the masking material. Since a dedicated robot is required to be installed, a large amount of investment and labor are required in practice, and it is not a simple and versatile method.

On the other hand, as a technique for easily performing the peeling operation, Japanese Patent Application Laid-Open No. 56-61468 and Japanese Patent Publication No. 1-5398.
Japanese Unexamined Patent Publication No. 9 discloses a technique relating to an adhesive sheet. These disclosed techniques relate to a pressure-sensitive adhesive layer containing heat-expandable resin particles, and relate to a pressure-sensitive adhesive sheet that expands the heat-expandable resin particles by heating to reduce the adhesive force, and is peeled off after use. It was a technology characterized by being easy to do. However, if the adhesive sheets according to these disclosed techniques are actually used, all the sheets cannot be completely removed and peeled off by simply heat-treating, and even if the adhesive force is lost, the sheets are in a stuck state. The sheet could not be completely removed and peeled off unless some physical factor such as touch was given.

[0005]

2. Description of the Related Art In view of the above situation, the inventor of the present invention has already invented and applied for an "automatic falling-off masking material". The technology already applied for by this inventor is an "automatic falling-off type masking material" according to Japanese Patent Application No. 2-203180. The technology according to this application is composed of a support, a pressure-sensitive adhesive layer containing a foaming agent provided on one surface of the support, and a shrinkable base material layer provided on the other surface of the support. It was an automatic captive masking material characterized by

[0006]

The technique already filed by the present inventor is an excellent technique that can be easily unmanned and removed after attachment, but since the foaming agent contains a heat insulating effect. However, the heat transfer to the pressure-sensitive adhesive layer containing the foaming agent is delayed, and it may be necessary to remove the foaming agent manually or by using a physical means such as an automatic robot.

[0007]

According to the present invention, a support and
This support comprises a pressure-sensitive adhesive layer provided on one surface and a shrinking base material layer provided on the other surface of the support. The pressure-sensitive adhesive layer contains a foaming agent, To solve the above-mentioned conventional problems by providing an automatic captive masking material characterized in that a heat conduction hole is provided on the entire surface of a base material layer.

[0008]

[Function] Since heat is effectively transmitted to the pressure-sensitive adhesive layer through the heat-conducting holes provided on the entire surface of the shrinkable base material layer, the heat-foaming rate of the pressure-sensitive adhesive layer is promoted, which ensures reliable unmanned operation. Can be removed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic captive masking material according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the automatic captive masking material according to the present invention.
In the figure, (1) is an automatic captive masking material according to the present invention,
(2) is a support, (3) is a pressure-sensitive adhesive layer, (4) is a shrinkable base material layer, and (5) is a release paper. In this invention, the pressure-sensitive adhesive layer (3) contains a foaming agent, and the shrinkable base material layer (4) is provided with heat conduction holes (41) on the entire surface.

As a material for the support (2), a pressure-sensitive adhesive layer (3), which has self-supporting property and is described in detail later, may be provided on one surface and a shrinkable substrate (4) may be provided on the other surface. Any material can be used as long as it has a strength such that it does not undergo transformation or deformation, and specific examples thereof include films such as polyester film, polypropylene film and polystyrene film. The thickness of the support (2) is preferably 25 to 500 μm. Further, as the shape of the support (2), a flat shape such as a tape shape, a label shape, a wide band shape, a sheet shape or the like can be preferably used.

In the present invention, the pressure-sensitive adhesive layer (3) is
It is a pressure-sensitive adhesive layer that loses its tackiness by heat treatment after sticking to a necessary sticking part. As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer (3), usually used rubber-based, acrylic-based pressure-sensitive adhesive can be preferably used. As a specific example, natural rubber, rubber-based polymers made of various synthetic rubbers, alkyl ester-based polymers such as acrylic acid and methacrylic acid, alkyl esters such as acrylic acid and methacrylic acid (about 50 to 95% by weight). ) And an unsaturated monomer copolymerizable therewith (about 0.5 to 50% by weight) as an acrylic polymer (average molecular weight 5000 to 3000000) as a base polymer. Examples thereof include polymers containing a crosslinking agent such as a polyisocyanate compound and an alkyl etherified melamine compound. When the cross-linking agent is blended, the blending amount is preferably 0.1 to 15 parts by weight with respect to 100 parts by weight of the base polymer.

The foaming agent contained in the pressure-sensitive adhesive layer (3) is a foaming agent that foams by heat treatment. The material of this foaming agent may be any material that foams by heat treatment, and specific examples include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, inorganic compounds such as azides,
Azobisisobutyronitrile, azodicarboxamide, azo compounds such as barium azodicarboxylate, toluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfohydrazine, 4 4'-oxybis (benzenesulfohydrazide), Hydrazine compounds such as allylbis (sulfohydrazide), p-toluylenesulfonyl semicarbazide, semicarbazide compounds such as 4'-oxybis (benzenesulfonylsemicarbazide), 5-
In addition to organic compounds such as N-nitroso compounds such as morpholyl-1,2,3,4, -thiatriazole, expandable microspheres such as microcapsules can be used.

The blending amount of the foaming agent differs depending on the type of pressure-sensitive adhesive, such as the degree of adhesion and bulk specific gravity, and the foaming characteristics differ depending on the type of foaming agent used, heating conditions and the like. , For example when using the base polymer as a pressure sensitive adhesive usually 100
Add 5 to 300 parts by weight of blowing agent to parts by weight. Further, as the setting condition of the blending amount of the foaming agent, it is preferable to set the amount such that the pressure-sensitive adhesive layer (3) is more than doubled by the foaming of the foaming agent. The reason for this is that, particularly when used as an undercoat masking material for the wire harness wiring hole portion at the time of coating an automobile anticorrosive paint, it is likely to fall off from the adhered portion.

Further, as a condition for setting the blending amount of the foaming agent, foaming is performed so that the foaming of the foaming agent of the pressure sensitive adhesive layer (3) is completed by heating at 100 to 150 ° C. for about 1 to 5 minutes. It is preferable to set up a system of agents. The reason for this is that this heating condition is usually used in the drying process for coating an automobile anticorrosive paint. The thickness of the pressure-sensitive adhesive layer (3) may be set according to the type and blending amount of the foaming agent, the type of adhesive, heating conditions, intended use, etc., but is not particularly limited, but has been described above. When used as an undercoat masking material for the wire harness wiring holes when coating automotive rust-preventive paint under set conditions, a thickness of 25 to 500 µm is usually suitable.

The shrinkable substrate (4) used in the present invention is a substrate that shrinks by heat treatment. The material of the shrinkable base material (4) may be any material that shrinks by heat treatment, and specific examples thereof include films made of polyethylene, polyester, etc., polyethylene foam, urethane foam, and the like.

Further, in the present invention, the shrinkable substrate (4)
A heat conducting hole (41) is provided on the entire surface. The reason for this is that by providing the heat transfer holes (41) in the shrinkable base material (4),
This is because the heat conduction to the pressure-sensitive adhesive layer (3) at the time of heating is efficiently performed through the heat conduction holes (41). In other words, the foaming agent contained in the pressure-sensitive adhesive layer (3) is foamed by the heat conduction hole (41) in a short time, and the automatic captive masking material (1) is easily and reliably unattended. Because it will be dropped below. The size of the heat conducting hole (41) is not particularly limited, but one having a diameter of about 0.2 to 3 mm is
It is preferable in terms of production and use.

As a method of providing the shrinkable substrate (4) on the support (2), a method of using an adhesive or a pressure sensitive adhesive can be exemplified.

The release paper (5) is a member provided to maintain the tackiness of the pressure-sensitive adhesive layer (3) until the time of use, and is peeled off before use.

FIG. 2 shows a first modified example of the automatic captive masking material (1 ) shown in FIG. 1, which is the release paper (5) used in the above-mentioned embodiment.
It is a laminate of self-removing masking materials (1 ) without using. The automatic captive masking material of the first modified example
In (1) , the sticking workability can be improved.

FIG. 3 shows a second modification of the automatic captive masking material (1) shown in FIG. 1, which is the release paper (5) used in the above embodiment.
In a modification using a carrier sheet (6) instead of the carrier sheet (6), this carrier sheet (6) is in a roll shape or a foldable type, and a large amount of automatic falling type masking material is used.
It has a structure that can store (1) , and a large amount of automatic captive masking material (1 ) can be peeled off from this carrier sheet (6) one after another, and can be attached to the attaching part, so that automatic operation with good workability is possible. It is used as a falling-type masking material (1) .

Next, the use state of the automatic drop-off type masking material (1) having such a structure will be described. Figure 4 is a diagram showing a state in which stuck to the automatic ejecting type masking member (1), FIG. 5 is a diagram showing a state in which the bonded been automatic ejecting type masking member (1) falls off ..

The self-removing masking material (1) from which the release paper (5) has been peeled off is attached to the periphery of the wire harness wiring hole (7) where masking is required as shown in FIG. After the coating is completed, the pressure-sensitive adhesive layer (3) of the automatic drop-off type masking material (1) is heat-treated to remove the foaming agent contained in the pressure-sensitive adhesive layer (3) as shown in FIG. It foams and the foamed foaming agent (8) swells the pressure-sensitive adhesive layer (3) to lose the adhesive force.

Simultaneously with this heat treatment, the shrinkable substrate (4)
Contracts, and as shown in FIG. 4, the central part is bent when viewed from the side of the support (2), and the contracted base material (4) is bent to bend the support (2) and the support (2). The pressure-sensitive adhesive layer (3) provided in () also bends. At this time, since the heat conduction speed (41) is promoted by the heat conduction holes (41) provided on the entire surface of the shrinkable base material (4), the foaming agent (8) contained in the pressure-sensitive adhesive layer (3).
As a result, the foaming speed can be increased and reliable foaming can be achieved. That is, this self-removing masking material (1) has the function of eliminating the adhesive force of the pressure-sensitive adhesive layer (3) of the foamed foaming agent (8) and the function of contracting and bending the shrinkable base material (4). And at the same time by heat treatment,
These effects are efficiently performed by the heat conduction holes (41), and as a result, the synergistic effect of these effects results in an automatic captive masking material.
(1) automatically comes off from the attachment part.

[0024]

[Test Example] The test example is shown below to further clarify the automatic captive masking material. (Test Example 1) 2 parts by weight of a polyisocyanate-based crosslinking agent based on 100 parts by weight of a copolymer composed of 70 parts by weight of acrylic acid ethyl ester, 30 parts by weight of 2-ethylhexyl, 5 parts by weight of methacrylic acid, and 0.2 parts by weight of acrylic acid. , Heat-expandable microspheres as a foaming agent {trade name: Matsumoto Microspheres, manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.} 30 parts by weight, dibutyltin laurate 0.05 parts by weight, phenolic resin 15 parts by weight as a solvent Were mixed and adjusted to obtain a pressure-sensitive adhesive containing a foaming agent. The pressure-sensitive adhesive containing this foaming agent was treated for easy adhesion with a thickness of 25 μm.
The polyester film was coated on one surface and dried, and the thickness after drying was applied to 40 to 100 μm. On the other hand, a polyethylene film, a polyethylene foam, a urethane foam, and a polyethylene non-crosslinked foam with 0.2 to 3 mm diameter heat transfer holes are adhered to the other surface of a polyester film coated with a pressure-sensitive adhesive in a thickness of 40 μm. did.

The adhesive force and shrinkage ratio of the thus-obtained automatic falling masking material were measured. JIS C,
2107, 6.2 method. The shrinkage ratio was measured by placing a 100 mm square sample in an atmosphere at 120 ° C for 5 minutes and measuring the length in the MD direction. (Shrinkage rate = 100−length after heating / 100 × 100) The measurement results of the adhesive force are shown in Table 1, and the measurement results of the shrinkage rate are shown in Table 2.

(Test Example 2) The automatic captive masking material (A) used in Test Example 1 and the same automatic captive masking material (B) as in Test Example 1 except that the heat conducting hole was not provided. Was used to test the degree of foaming of the foaming agent contained in the pressure-sensitive adhesive of each of these masking agents (A) and (B). The test was carried out by blowing hot air directly onto the foam, and the falling time of these masking agents (A) and (B) at each temperature was measured. The results are shown in Table 3.

[0027]

EFFECTS OF THE INVENTION The automatic shedding type masking material according to the present invention comprises a support, a pressure-sensitive adhesive layer provided on one side of the support, and a shrinkable base material layer provided on the other side of the support. And a pressure-sensitive adhesive layer containing a foaming agent,
Since the heat-conducting holes are provided on the entire surface of the shrinkable base material layer, it is an automatic captive masking material, so that heat can be efficiently conducted during heating, and it can be simply and surely attached after being attached. It has an excellent effect that it can be removed unmanned, and that it does not cause any bad damage to the rust-preventive coating film, and that it retains its aesthetic appearance even after coating.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an automatic captive masking material according to the present invention.

FIG. 2 is a first example of an automatic captive masking material according to the present invention.
It is a perspective view which shows the example of a change.

FIG. 3 is a second view of the automatic captive masking material according to the present invention.
It is a perspective view which shows the example of a change.

FIG. 4 is a cross-sectional view of a state of use showing a state in which the automatic drop-off type masking material according to the present invention is attached.

FIG. 5 is a cross-sectional view of a state of use showing a state in which the attached automatic fall-off type masking material shown in FIG. 4 falls off.

[Explanation of Codes] 1 Automatic falling-off masking material 2 Support 3 Pressure-sensitive adhesive layer 4 Shrinkage base material layer 41 Thermal conduction hole

[Table 1]

[Table 2]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C09J 7/02 JLF 6770-4J

Claims (2)

[Claims] 1. A pressure-sensitive adhesive layer comprising a support, a pressure-sensitive adhesive layer provided on one surface of the support, and a shrinkable base material layer provided on the other surface of the support. Is a foaming agent, and the shrinkable base material layer is provided with heat conducting holes over the entire surface thereof. 2. The foaming agent is made of a material that foams when heated, and the shrinkable base material layer is made of a material that shrinks when heated.
The automatic captive masking material described in.